| 摘要 |
PURPOSE:To detect the focusing of even an endoscope with a dark optical system securely with high precision by transmitting light from an external intense light source to a photographic adapter through a light guide and lighting up objects to be photographed through the opening part of a optical focusing system. CONSTITUTION:The light emitted from the intense light source 14 illuminates objects (a)-(c) to be photographed [while (b) is in focus] through the optical system consisting of a light guide cable 15, pinhole 19, photographic lens 8, and endoscope 4. Light reflected by a half-mirror 13 also illuminates the objects (a)- (c) to be photographed through the photographic lens 8. Reflected light from the object (b) is image-formed on the pinhole 19 through the photographic lens 8 and never reaches the photoelectric surface 20 of a photodetector 12 for focusing detection. A focusing state is obtained by moving the photographic lens 8 so that the output of the photodetector 12 is minimized, and a lamp 23 turns on. Therefore, the focusing detection of even the endoscope with a dark optical system is performed securely with high precision. |
